Their keepers cage a female bear and a male dog together when they are in heat, so that pressed by their natural urges, they convert their cruelty into love.
Black bear, Ursus americanus|
|Brown bear, Ursus arctos|
This cross, which is interfamilial (Canidae × Ursidae), is listed in various older works. For example, the following is an article quoted in its entirety from the American Veterinary Review (1905-6, vol. 29, p. 408):
|Woodcut illustration of an alleged bear-dog hybrid (Boaistuau 1591, p. 206)|
|17th-century depiction of a mastiff (from the University of Toronto Wenceslaus Hollar Digital Collection)|
Elizabethan bear baiting|
An account of Elizabethan bull and bear baiting
“There is still another place, built in the form of a theatre, which serves for the baiting of bulls and bears they are fastened behind and then worried by great English bull-dogs but not without great risk to the dogs from the horns of the one and the teeth of the other; and it sometimes happens that they are killed upon the spot, fresh ones are immediately supplied in the places of those that are wounded or tired.” (from Travels in England During the Reign of Queen Elizabeth by Paul Hentzner and Sir Robert Naunton)
On bear baiting
(from Chambers 1864)
“In the twelfth century, the baiting of bulls and bears was the favourite holiday pastime of Londoners; and although it was included in a proclamation of Edward III, among ‘dishonest, trivial, and useless games,’ the sport increased in popularity with all classes. Erasmus, who visited England in the reign of Henry VIII, speaks of ‘many herds’ of bears regularly trained for the arena; the rich nobles had their bearwards, and the royal establishment its ‘master of the king’s bears.’ For the better accommodation of the lovers of the rude amusement, the Paris Garden Theatre was erected at Bankside, the public being admitted at the charge of a penny at the gate, a penny at the entry of the scaffold, and a penny for quiet standing. When Queen Mary visited her sister during her confinement at Hatfield House, the royal ladies were entertained with a grand baiting of bulls and bears, with which they declared themselves ‘right well contented.’ Elizabeth took especial delight in seeing the courage of her English mastiffs pitted against the cunning of Ursa and the strength of Taurus. On the 25th of May 1559, the French ambassadors ‘were brought to court with music to dinner, and after a splendid dinner, were entertained with the baiting of bears and bulls with English dogs. The queen’s grace herself, and the ambassadors, stood in the gallery looking on the pastime till six at night.’ The diplomatists were so gratified that her majesty never failed to provide a similar show for any foreign visitors she wished to honour.”
Fossils demonstrate the former existence of animals known as bear-dogs (Family Amphicyonidae, 46.2-1.8 mya) and dog-bears (Family Hemicyonidae, 33.9–5.3 mya). These creatures were so named because they had both bear- and dog-like traits. An example of the bear-dog Amphicyon, is shown above and an artist's reconstruction of the dog-bear Hemicyon appears below.
The Denver hybrid was the alleged result of a serendipitous mating between a domestic dog and a wild bear, but there are old reports of this cross occurring in captivity as well.
Writing during the Elizabethan era, the French humanist Pierre Boaistuau, in his Histoires prodigieuses, says dogs and bears were intentionally mated in London and that sometimes a hybrid resulted. He includes an artist’s illustration of a supposed hybrid (shown at right). Bears and dogs, usually mastiffs, were kept to fight in the bear baitings so popular at the time and a favorite pastime of the Queen. An English translation of the passage in question (Boaistuau 1591, pp. 206-209) reads as follows:
Boaistuau then turns to a discussion of other types of hybrids, but eventually returns to his description of the bear-dog:
The exact identity of the bears involved in Elizabethan bear baitings is somewhat in doubt. But it does seem that the Brown Bear (Ursus arctos) is the animal in question. As Henry Reeks (1878) states in a scholarly article on mammals mentioned by Shakespeare, the brown bear (he refers to Ursus arctos and to its synonym Ursus isabellinus) “would probably be the bear with which Shakspeare [sic] would be most familiar. Bear baiting seems to have been a very popular amusement about that period and for many years subsequently.”
Though one might suppose that a brown bear would be far too large to mate with a dog, there is a very wide range of geographic variation in the adult size of these animals. Nowak (1999, pp. 685-686) states that while brown bears may weigh as much as 780 kg (1720 lbs) on the southern coast of Alaska, elsewhere they can be far smaller. For example, the average figure he gives for southern Europe is just 70 kg (154 lbs). It does seem, then, that some bears would be within the size range that would allow mating with a large dog.
Jakob Benjamin Fischer, too, in his Naturgeschichte von Livland (1791, p. 146), mentions a bear-dog hybrid that was supposedly fertile. He gives the cross in the same direction as in the account of the Denver hybrid (female dog/male bear), but in the opposite direction from that specified by Boaistuau:
Of course, nowadays dogs and bears are very rarely kept caged together, and there seem to have been no attempts to cross them by artificial insemination. Therefore, in the absence of experimentation, it must remain an open question whether the various early reports of this type of hybrid have any basis in fact.
Naturally, there are, as with many other types of hybrid crosses, those who say that such a hybrid is impossible. For example, the following is taken from the English Cyclopaedia (1866, p. 433):
The gestation periods of dogs and bears do differ widely (a little over two months in the former versus 7 months in the latter). However, we also need hardly observe that in every hybrid cross, the parents differ to some degree. And that difference is larger in some crosses than in others.
Though much is believed and much has been said with regard to this matter, it is in fact unknown exactly how different two animals can be and still engender hybrids together. More specifically, it is still unknown just how different the gestation period lengths of two organisms can be if hybrids are to be produced. All we can say for sure is that hybrids between parents with differing gestation periods are known.
Indeed, in any hybrid cross where the gestation periods (or, in birds, the incubation periods) differs in length between the parents, the typical finding is for the period in the hybrid to fall about halfway between. But the whole notion of gestational periods as a criterion of ability to hybridize seems to be established only by tradition (the idea dates back 2,000 years to Pliny and Aristotle) and scientific investigation of the issue has been next to nil. Indeed, it is well known today that certain pairs of parents with markedly different gestational periods can hybridize. For example, bottle-nosed dolphins and false killer whales can cross, as documented in the following cross account taken from the dolphin hybrids page of this website (note, too, that the dentitions differ hugely here, as well):
The chromosome counts of dogs and bears are fairly similar (in dogs, 2n=78, in both black and brown bears, 2n=74).
See also: Scherren (1907, pp. 432-433).
Bear-dog Hybrids - © Macroevolution.net
By the same author: Handbook of Avian Hybrids of the World, Oxford University Press (2006).
|The Paris Garden Theatre, Bankside, the primary venue for bear baitings in old London (engraving from Chambers 1864, vol. II, p. 57)|